By D. Karmok. Concordia College, Austin Texas.
Typically buy baycip 500mg low price, Application of knowledge of genetics to understand the the centromere is not midway between the two ends of heritable basis of the diseases and to improve the man chromatids discount baycip 500 mg amex. When chromatid has a short arm and a long agement of diseases through gene intervention baycip 500 mg otc, is called arm, the chromosome is called submetacentric. Mendel’s work in 1886 that hereditary of the chromatid are of equal length, the chromosome is characteristics are transmitted to offspring by separate metacentric, if one arm is too short the chromosome is units laid the foundation of genetics. Later, Johannied, acrocentric and if centromere lies at one end (each chro the Danish botanist in 1909 termed these units as genes matid has only one arm), the chromosome is telocentric and, Morgan, the American geneticist established that (Figs. Chromosomes are distinguishable only the hereditary characteristics are transmitted on chromo during mitosis. Karyotyping is done for studying the a cell (all chromosomes put together) is represented by about 6 × 109 morphology and number of chromosomes. The Y chromosome, which is the smallest by arresting the dividing cells in metaphase by colchicine and spreading chromosome, contains 5 × 107 nucleotide pairs. In many cases, chromosomal abnormalities can be correlated with specific diseases. A nucleotide consists of a nitrogenous base, a nuclei and mitochondria of all eukaryotic cells. About 25 millions of nucleosomes genous bases are often designated by their first letter i. The purine and pyrimidine bases encode genetic acetylation of histone loosens the coiling and pairs of message (Application Box 5. The amino acid sequence in the protein synthesized in the cell decides the text of the message. Important Note Gene and Proteins: A gene is defined as the amount of information necessary to specify a single protein molecule. Proteins determined by a single gene may divide to form different proteins with various physiological actions. Double Helix Structure In the double helix, the sugar phosphates form the back bone with all the bases being present inside the helical Fig. The total genetic information stored in chromosomes a molecule of phosphate and a base (Fig. In each pair, one is derived from the mother and nine in one chain always pairs with the pyrimidine base the other from the father. Similarly, adenine always pairs chromosome is inherited from the mother, and the with thymine. The condition is passed to all the somatic cells, while the germ cells in known as trisomy 21. That means ovary will have is called mongolism, or Down’s syndrome, which is always active X chromosome. The inactive X chromosome in the somatic cells in malies and abnormal physical features (Fig. This phenomenon in females helps in chromosomal abnormality in female is Turner syn- nuclear sexing (Clinical Box 5. During fertilization of an ovum by a sperm, the dip loid number is restored, so that each cell carries 23 lities. X-linked Disorders: An abnormal gene located in an done for genetic female testing by preparing and staining the smears autosome leads to an autosomal trait; whereas loca of squamous cells scrapped from oral cavity or by identifying Barr body attached to nuclear lobes in the circulating neutrophil, in females. A tion of abnormal gene in a sex chromosome gives minimum of 30% cells positive for sex chromatin indicates the person rise to sexlinked traits. Very few of them Chromosomal abnormalities may be either due to the are Xdominant, but most are Xrecessive. Therefore, defect in autosomes or in sex chromosomes, and are many X-linked disorders do not manifest in females accompanied by congenital abnormalities. Trisomy 21: the commonest abnormality of autosomal linked genetic disorders at all times manifest in males chromosome is the presence of three instead of two as they do not have normal neutralizing X allele. There are noncoding region (three regulatory regions) and coding region (exon and intron). The inherent control mechanisms are such that only removed during posttranscriptional events and adjacent selected genes are switched on at any given time. Genetic expression occurs in two broad steps: trans start site before it can move forward to begin trans cription and translation (Flowchart 5. The promoter separates from the exons and introns by about ten nucleotides known as the operator. There is often another regulatory nucleotide plate strand (also called, coding strand or sense sequence at the other end known as 3’ region. Post-translational modification: Posttranslational modi fications such as proteolytic degradation, hydroxy Ribonucleic acid is made up of a single chain of poly lation, glycosylation, etc. The sugarphosphate that forms the backbone con development of drug resistance by cancer cells to tains ribose instead of deoxyribose. Gene rearrangement: This enhances the generation of antigen specific immunoglobulins. It forms the template that directs the synthesis of nology, hormones like insulin, growth hormone, erythro protein molecules within ribosomes. Following the hybridization reaction, the membrane is washed and regions of hybridization are identified by Embryo Cloning autoradiography. The detection of mutant gene that causes diseases like cystic aim of this is not to create a cloned human being, rather fibrosis. Stem cells are extracted in the blastocyst stage Northern blotting of development, which can practically generate any type Northern blotting is similar to southern blotting except of cells in the human body. Western blotting Tissue Cloning Western blotting is used for identification of specific pro This technique is called tissue culture, in which cells are teins. The known mutagens are Xrays, ultra Cloning means production of many identical copies of a violet light, certain chemicals, etc. Generally, there are four types of cloning: Gene of mutations: Point mutation and frameshift mutation. Gene clon Frame-shift Mutations ing is used widely in genetic engineering for sequencing In this mutation, base pairs are either deleted or inserted genomes and in gene therapy. The However, translation continues and proteins formed have Broad methodology: many altered amino acid sequence. The technique of reproductive cloning uses the prin Mutation results in diseases such as sickle cell disease, ciple of somatic cell nuclear transfer, in which genetic phenylketonuria, cystic fibrosis, etc. Chromosomal translocation: In this, a part of chro mosome is translocated to other chromosome. For Genetic screening is detecting the genetic variations in a example, an area of chromosome 8 in patients with human being. It is used for diagnosing diseases at various Burkitt’s lymphoma is translocated to either of the stages and for various purposes such as prenatal diagno chromosome 2, 14 and 22. Missense mutation: In this, amino acid sequence of protooncogene changes that helps the protein to con Prenatal Diagnosis vert into oncogene. Gene amplification: Amplification of some of the in the fetal stage and therefore has preventive values.
Care should should instruct their support staff to avoid recommend- be exercised to select the correct ft in order to avoid ing lotion moisturizers as they do not afford the appro- ocular discomfort and trauma buy baycip 500 mg low price. Upon removal post- priate lipid content during the catabolic post-treatment procedure discount baycip 500 mg with visa, any residual petrolatum should be removed phase cheap baycip 500mg on line. In most cases, erythema lasts no more than using a sterile saline wash, helping minimize the 1 week and is treated with a brief course (24–48 h incidence of blurry vision postoperatively. Saline post-procedure) of topical high-potency corticoster- moistened gauze pads may be substituted for eye oids. In rare instances, patients experience itching may shields if the periorbital region will not be treated. Some experienced laser surgeons caution against the use of topical anesthesia due to concerns about tis- 46. This has even with adjunctive cooling methods, resulting in led to some physicians switching to liposomal lido- some degree of pain intraoperatively. W hen break- caine preparations, tumescent anesthesia, or regional through pain is experienced during nonablative laser nerve blocks supplemented with a sedative and analge- treatment, the laser operator should stop treatment sic combination delivered orally, intramuscularly, or and immediately attend to the patient’s discomfort by intravenously. Rarely, pain is may be used without any anesthetic administration intolerable and, if so, the treatment session is best prior to treatment; however, this is rarely the case and discontinued. The post-operative risks should be dis- patient comfort should supersede all other goals. The cussed with all patients prior to treatment and include specifc techniques used for each laser are described infection, bruising, punctate bleeding, redness, swell- below in their respective sections. Finally, patients are ing, blistering, reactivation of herpes, pigmentary optimally placed in the supine position during treat- alteration, and scarring. This helps to ensure patient safety in those rare ing treatment with a 1,540 nm erbium:glass laser, exfo- cases of vasovagal reaction. Pregnant women may experience 46 Emerging Technologies: Nonablative Lasers and Lights 609 focal hyperpigmentation following nonablative laser deposition. These results were consistent with the therapy; however, expecting mothers should be reas- blinded observer ratings showing that 9/10 with mild sured that, at this time, there is no evidence of any risk to moderate and 4/10 with moderate to severe wrinkles to the fetus. Increasing the number of passes at subpurpuric fuences did not further enhance dermal 46. Similar results were observed in another study using a 585 nm system and a 350 ms Devices used for the treatment of vascular lesions pulse duration at 6 months post-treatment. In either case, a total of 3–6 treatments were devices are available at slightly longer wavelengths of required for maximal improvement. Thus, it appears 585 and 595 nm and employ pulse widths of 350 ms to that vascular lasers may also fnd use for nonablative 40 ms at fuences of 3–10 J/cm2. A reduction in the repetition rate to increase cryogen-spray cooling or continuous delivery of the interval between pulses may be employed to reduce chilled air is utilized. Immediately upon functions at 595 nm with a 7 or 10 mm spot size and administration of the pulse, the patient will feel a rub- 0. Persistent purpura or epidermal whitening have reported mild improvements in skin elasticity, correlate with post-treatment blistering and observa- dyschromia, and texture post-operatively. Others treat- tion of either intraoperatively requires a reduction of ing off-the-face have also observed some improvement laser parameters. The nature of this improvement may be via a reduction of dermal vasculature or through collagen remodeling, as evi- 46. M ore recently, a 1,550 nm Although not as popular in the United States, the erbium-doped fber laser that also utilizes water as a 1,540 nm erbium:glass laser has been well studied in chromophore known as the Fraxel® was developed Europe. The Aramis laser employs a infrared laser facial treatments have been studied 4 mm spot size, 3. Proflometry studies revealed a 40% reduc- laser marketed to physicians for medical use. It tion in rhytids with a concurrent 17% increase in epi- employs a 10 mm spot size and 200 ms pulse dura- dermal thickness 6 weeks following a series of four tion. These fndings were confrmed by digital ing coeffcient at 1,320 nm, allowing for bulk dermal photography and ultrasound imaging. Thus, dermal showed histological evidence that treatment with the vasculature is targeted in addition to dermal collagen, 1,540 nm laser induced dermal collagen remodeling; which is denatured at temperatures of 60–70°C. The these effects correlated with patient satisfaction and Cooltouch handpiece possesses a thermal sensor that very few adverse events. However, our clinical experience has feedback system until reaching the optimal range of shown that the degree of histological collagen remod- surface Tmax between 42 and 48°C. A number of eling does not always translate into predictable clinical studies have shown that treatment with the 1,320 nm changes, partly explaining the broad range of improve- laser induces vascular damage, apoptosis, and edema ment reported in the literature (10–85%). These effects in combination result in challenge for future development will be to optimize the release of infammatory mediators that lead to laser parameters in a manner that allows for more pre- neocollagenesis. This wavelength the dependence of current nonablative devices on sig- also relies on water as the chromophore to affect dermal nifcant epidermal cooling. The Smoothbeam utilizes a 250 ms pulse dura- dermal thermal injury, in fact, the healing process may tion, slightly longer than the Cooltouch. However, it not fully recruit the epidermal stem cell population and does not have a thermal sensor feedback system its contribution to dermal remodeling. Comparisons of the Cooltouch and ple, namely the Fraxel® (Reliant Technologies, Inc. The Fraxel® laser is purported rhytids, although one study showed superior effcacy to bridge this gap, by providing increased reliability with the 1,450 nm diode laser for recontouring atrophic and predictable clinical effcacy while maintaining a acne scars when using fuences of 9–14 J/cm2. Unlike other nonablative Interestingly, the 1,450 nm diode laser appears to dam- devices, Fraxel® does not have as a goal the complete age sebaceous glands with one study demonstrating sparing of the epidermis; therefore, contact cooling is effcacy for the treatment of active acne. The Fraxel® the 1,450 nm diode have been clearly attributed to the laser utilizes a non-stationary handpiece capable of 46 Emerging Technologies: Nonablative Lasers and Lights 611 Fig. The 1,550 nm rapid healing times are explained by the combination erbium-doped fber laser also utilizes water as a chro- of interlesional sparing and treatment of the epidermis mophore, but delivers a microarray pattern instead of a which promotes rapid reepithelialization. Since each beam maintains the same energy 4–6 treatment sessions in 1–2 week intervals. A recent profle, interbeam fdelity is ensured, a feat not yet histological study has uncovered the mechanism proven possible through the use of microarray flters. Blinded assessors reported a 25–50% clinical improvement in 91% of patients after a single treat- ment and a 51–75% improvement noted in 87% of 46. The side effect profle was similar across all Thus far, the focus has been turned to laser energy Fitzpatrick skin types. Recent advances have led to the availability of ble at the fnal 6 month follow-up, a renewed excitement suffciently powered light sources for use in medicine 46 Emerging Technologies: Nonablative Lasers and Lights 613 a b Fig. Pulse stacking is possible with tems employ a high-intensity polychromatic light certain different interpulse delays, theoretically allow- source in the range of 400–1,200 nm and rely on the ing for deeper heat transfer to larger caliber vessels or principle of selective photothermolysis. The emission hair follicles as the smaller more superfcial structures occurs as a pulsed light across this broad band, although cool.
Scarring is a dreaded complication and for- till melanocytes migrate from the surrounding skin tunately proven baycip 500 mg, very uncommon purchase baycip 500 mg free shipping, after superfcial peels generic 500mg baycip free shipping, but 14 Facial Peels 175 Table 14. W hen applied over large areas over a short period of time or under-occlusion, phenol can cause systemic toxicity by absorption. Hence cardiac status must be continuously monitored and intravenous hydration be can occur with medium depth and deep peels. Peeling must be done in with a history of poor wound healing, keloid forma- small segments and completed before moving to the tion, and developing post-peel infection are at a higher next cosmetic unit, to reduce systemic absorption. Abnormal scarring has been reported with Since phenol is metabolized in the liver and excreted patients on isotretinoin. In severe cases, there can be by the kidney, it should not be used in patients with ectropion or eclabion. Khunger Resorcinol can also produce toxicity, if applied in customizing techniques give chemical peeling a newer excess. Diarrhea, vomiting, severe headache, dizzi- dimension for treating patients optimally, with greater ness, drowsiness, bradycardia, dyspnea, and paralysis versatility and satisfaction, and enhanced safety at the are presenting features. Hence chemical peeling is a versatile tool cinism is to restrict the area of application or limit the that can help build a good aesthetic practice, with min- concentration of resorcinol. Toxicity with salicylic acid is not observed when it is applied on the face but has been reported when large amounts of 50% salicylic acid paste are applied to 50% References or more of the body surface, under occlusion. Khunger N, Arsiwala S (2009) Combination and sequential uncommon in well-trained hands if done with proper peels. In: Khunger N (ed) Step by step chemical peels, precautions following safety guidelines for different 1st edn. Jaypee Brothers M edical Publishers Ltd, New Delhi, pp 202–218 types of skins . Informa Healthcare, New York, pp 53–54 There has been a tremendous increase in procedural 5. In: Khunger N (ed) Step by majority of chemical peeling procedures ft into this step chemical peels. It is a simple offce procedure, requiring no Dermatol Surg 23(1):23–29 machines, affordable to every physician, and easy to 8. A wide variety of chemical agents ment of acne scars with trichloroacetic acid: chemical recon- struction of skin scars method. Dermatol Surg 28(11): are available and treatment can be individualized, 1017–1021 according to skin type and requirement of the patient. Bhardwaj D, Khunger N (2010) An assessment of the eff- the downside to peeling is that it is a slower process. Erbil H, Sezer E, Taştan B, Arca E, Kurumlu Z (2007) Facial peeling results in the removal of superfcial Effcacy and safety of serial glycolic acid peels and a topical skin lesions, reducing excess pigmentation, regenera- regimen in the treatment of recalcitrant melasma. J Dermatol tion of new tissue with improvement of the skin texture 34(1):25–30 and long lasting therapeutic and cosmetic benefts. Dermatol Surg 23(3):171–174 peeling agents and techniques, in order to maintain 13. A patient may require different peeling agents peel method for benign pigmented lesions in dark-skinned patients. Dermatol Surg 30(4 Pt 1):512–516 at different concentrations over a period of time and 14. In: Khunger N, Sachdev these should be customized and selected accordingly M (eds) Practical manual of cosmetic dermatology and for maximum beneft. Ghersetich I, Brazzini B, Peris K, Cotellessa C, M anunta T, (alpha-hydroxy acid) peels with nonablative lasers, intense Lotti T (2004) Pyruvic acid peels for the treatment of pulsed light, and trichloroacetic acid peels. Elsevier Inc, Philadelphia, pp 137–170 fcial glycolic acid (alpha-hydroxy acid) peels with micro- 26. Landau M (2007) Cardiac complications in deep chemical Sachdev M (eds) Practical manual of cosmetic dermatology peels. Indian J Dermatol Venereol Leprol 74(Suppl): cosmetic outcomes by combining superfcial glycolic acid S5–S12 Fractional Laser Resurfacing 15 Vic A. Non ablative fractional laser resurfacing has an intact stra- Fractional laser resurfacing is rapidly gaining tum corneum, while ablative fractional laser resur- momentum as the treatment of choice for facial and facing does not leave the stratum corneum intact. Traditional ablative laser the times of re-epithelialization also vary, with non resurfacing, although effective, is losing popularity ablative fractional laser resurfacing producing a rapid due to signifcant risks such as hypopigmentation, re-epithelialization in less than 24 h, while ablative scarring and prolonged erythema and limitation in fractional laser resurfacing producing a more delayed the treatment of lighter skin types. Both modalities resurfacing can be divided into nonablative and abla- create thermal zones of injury to the treated tissue, with tive, and the patient selection, treatment protocols nonablative fractional devices creating more micro- and pre- and postcare vary with these two modalities. Routine antibiotics are resurfacing not necessary, as infection is exceedingly rare. Higher energy settings and treat- Superfcial rhytids ment densities are required in patients with a history of acne scars, surgical and traumatic scars and moderate-to- deep rhytids. Treatment sessions are gener- 1,550 nm), moderate rhytides (1,550 nm) and superf- ally spaced 4–6 weeks apart but can be performed at cial rhytids (1,410 nm, 1,440 nm, 1,540 nm and longer treatment intervals . A test site is occasionally use 23% lidocaine/7% tetracaine or 30% 15 Fractional Laser Resurfacing 181 Table 15. The area is then wiped clean results are evident at 9–12 months after the fnal treat- prior to treatment. A thin coat of gel may be utilized to ment, with patients noticing continual improvement. Immediately after treatment there which is most noted in darker skin types, particularly is moderate erythema and slight edema and duskiness of East Asian skin types (Fig. Short-term complica- (Gentlewaves) is performed immediately posttreatment tions include acne fares, edema, erythema and peeling, to reduce posttreatment edema and erythema. Even though multiple treatments are necessary, devices can deliver excellent results with enhanced 182 V. Narurkar Before 1927 treatm ent Im m ediately post 1 day post 2 days post 3 days post 4 days post 5 days post 1 week post Fig. Our antibiotic with a history of adnexal disease– such as morphea, of choice is azithromycin (Z pack) to start the day scleroderma and other connective tissue disorders, before the procedure and continue for 3 days. Treatment with oral antibiotics remains cial areas such as the neck and chest are treated, controversial – we routinely treat patients with oral extreme caution is advised. Technique is key for all antibiotics in the pre- and posttreatment period, as areas, to avoid bulk heating which can produce adverse 15 Fractional Laser Resurfacing 183 Fig. Aggressive emol- liation with petrolatum-based products such as aquaphor are recommended until reepithelialization is complete. Common short-term adverse effects include crusting, weeping, erythema and edema, 15. If this is done, the Thermage treatment is skin resurfacing, they are limited for certain aspects of performed frst, followed by Fraxel. The combination facial aging such as dynamic rhytids, volume loss and approaches allow for synergy of these modalities. Narurkar considerably safer than traditional ablative laser resur- facing and both offer greater recovery and fewer short- and long-term side effects. Combination therapies with botulinum toxins, dermal fllers and radiofrequency complete the picture of fractional laser resurfacing with synergistic effects. Laubach H, Tannous Z, Anderson R et al (2006) Skin responses to fractional photothermolysis.
Arthritis and gout of the first metacarpal joint also may coexist with and exacerbate the pain and disability of de Quervain tenosynovitis effective 500 mg baycip. Transverse ultrasound image of the first dorsal compartment tendons (abductor pollicis longus and extensor pollicis brevis) showing tenosynovitis purchase baycip 500 mg amex. Activities associated with the development of de Quervain tenosynovitis include repetitive hand shaking baycip 500 mg otc, scooping ice cream, or using a screw driver. The pain of de Quervain tenosynovitis is sharp and constant and is exacerbated by any activities requiring active pinching of the thumb or ulnar deviation of the wrist. The pain is localized to the area over the radial styloid process and is associated with increasing functional disability if the inflammatory process remains untreated. On physical examination, there is tenderness and swelling over the tendons and tendon sheaths along the distal radius, with point tenderness over the radial styloid. A creaking tendon sign may be noted with flexion and extension of the thumb and triggering of the thumb may occur. Patients with de Quervain tenosynovitis demonstrate a positive Finkelstein test (Fig. The Finkelstein test is performed by stabilizing the patient’s forearm, having the patient fully flex his or her thumb into the palm, and then actively forcing the wrist toward the ulna. Patients suffering from de Quervain tenosynovitis will exhibit a positive Finkelstein test. Plain radiographs of the wrist are indicated in all patients suspected of suffering from de Quervain tenosynovitis to rule out occult bony pathology and to identify calcific tendinitis. Based on the patient’s clinical presentation, additional testing may be indicated, including complete blood cell count, uric acid, sedimentation rate, and antinuclear antibody testing. Magnetic resonance imaging and ultrasound imaging of the wrist is indicated to assess the status of the abductor pollicis longus and extensor pollicis brevis tendons and tendon sheath as well as to identify other occult pathology including arthritis and gout involving the first metacarpal joint (Fig. Longitudinal ultrasound image of De Quervain tenosynovitis in a volleyball player shows thickening of the extensor carpi radialis. With the patient in the above position, the radial styloid process and the abductor pollicis longus and extensor pollicis brevis tendons at that level are identified by palpation. Identification of the tendons is facilitated by having the patient radially deviate the wrist against the examiner’s resistance (Fig. At the level of the radial styloid a high-frequency linear ultrasound transducer is placed in a transverse position over the abductor pollicis longus and extensor pollicis brevis tendons and an ultrasound survey scan is taken (Figs. Color Doppler may aid in identification of the radial artery and help separate it with the superficial radial nerve which lies just radial to the radial artery (Fig. The tendons will appear as the hyperechoic “hole” in the hypoechoic tendon sheath. However, in a small number of patients, the tendon sheath will appear to travel through separate subcompartments divided by a subcompartmental septum (Fig. An effusion surrounding the affected tendons can often be identified with ultrasound imaging (Fig. When the tendon sheaths are identified, the tendons are evaluated for tendinopathy, tendinitis, effusions, tears, and ruptures (Figs. Color Doppler may aid in identification of neovascularity of inflamed tendons (Fig. Identification of the extensor pollicis brevis and abductor pollicis longus tendons is facilitated by having the patient radially deviate the wrist against the examiner’s resistance. Proper transverse position for the linear high-frequency ultrasound transducer to perform ultrasound evaluation for de Quervain tenosynovitis. Transverse ultrasound image demonstrating the relationship of the extensor pollicis brevis and abductor pollicis longus tendons within their tendon sheath at the level of the radial syloid. Transverse ultrasound image of the first dorsal compartment shows two subcompartments containing the extensor pollicis brevis and abductor pollicis longus tendons within. Longitudinal ultrasound view demonstrating effusion around the extensor pollicis brevis tendon. A: Ultrasound image longitudinal to the extensor pollicis brevis tendon (T) shows thickening of the overlying extensor retinaculum and synovial thickening (arrow). B: Ultrasound image transverse to the first wrist compartment shows retinaculum and synovial thickening (arrow) and abnormal hypoechoic thickening of the abductor pollicis longus tendon (arrowhead). Note the position of the retinaculum, which lies over the radial styloid to retain the abductor pollicis longus and extensor pollicis brevis tendons against it, and the cross- sectional appearance of the radial artery (a) while it crosses the first compartment to reach the dorsal wrist. C: 3D- volume ultrasound image with Z-plane reconstruction demonstrates an hourglass appearance of tendons (T) due to the constricting action of the thickened retinaculum (arrowheads). Note the obstructed gliding of superficial tendon fibers (arrowhead) against the thickened retinaculum. A: Tenosynovitis of the abductor pollicis longus and the extensor pollicis brevis in a patient with de Quervain disease. Note the large, homogeneously anechoic collection of synovial fluid with marked tendon sheath widening. The synovial fluid accumulation dislocates extensor tendons, thus allowing a careful assessment of their shape and profile. Longitudinal ultrasound image of the radial aspect of the left dorsal wrist showing significant thickening of the abductor pollicis longus tendon sheath (asterisk), appearances consistent with De Quervain tenosynovitis. High-resolution ultrasound in the diagnosis of upper limb disorders: a tertiary referral centre experience. However, de Quervain tenosynovitis pain is more common with activity, while the pain and numbness associated with cheiralgia paresthetica is present at rest. Treatment of de Quervain tenosynovitis with ultrasound- guided injections is a safe and effective approach so long as careful attention is paid to the location of the radial artery and superficial branch of the radial nerve (Fig. Careful neurologic examination to identify pre-existing neurologic deficits especially of the radial nerve that may later be attributed to the procedure should be performed on all patients before beginning ultrasound-guided injection for de Quervain tenosynovitis. Complications of surgery to treat de Quervain can often be diagnosed with ultrasonography (Fig. C: Oblique ultrasound image showing the gap (arrow) between the two neuromas (void arrowheads) of the superficial radial nerve. Ultrasound-guided injection of triamcinolone and bupivacaine in the management of De Quervain’s disease. Sonographic identification of the intracompartmental septum in de Quervain’s disease. Ultrasound-guided corticosteroid injection for the treatment of de Quervain’s tenosynovitis. Passing obliquely over the extensor carpi radialis brevis and extensor carpi radialis longus tendons of the second compartment are the abductor pollicis longus and extensor pollicis brevis of the first compartment which all intersect at their musculotendinous junctions (Fig. This intersection is just proximal to the extensor retinaculum which serves to tether down the tendons and may contribute to the evolution of intersection syndrome. The key landmark when performing ultrasound-guided injection for intersection syndrome is Lister’s tubercle and the intersection of the extensor carpi radialis longus, the extensor carpi radialis brevis, the extensor pollicis brevis, and the abductor pollicis longus tendons and tendon sheaths. Passing obliquely over the extensor carpi radialis brevis and extensor carpi radialis longus tendons of the second compartment are the abductor pollicis longus and extensor pollicis brevis of the first compartment which all intersect at their musculotendinous junctions.