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Assessing And Differentiating Common Skin Conditions
Lower extremity dermatological conditions can range from xerosis to squamous cell carcinoma. These speakers at the Western Foot and Ankle Conference discuss pearls on differentiating skin conditions, biopsy techniques, current treatments and coding.
Dry skin or xerosis is a loss of moisture and lipids in skin as a consequence of frequent bathing with excessively hot water and harsh soaps, according to Dock Dockery, DPM. He adds that dry skin can occur after prolonged exposure to low humidity as with forced air heating during the winter in cold climates or in very dry states. Xerosis can also be a normal consequence of aging.
Dr. Dockery says xerosis reduces the physical barrier against entry of irritants, allergens and pathogens.1 Xerosis increases a patient’s vulnerability to environmental triggers and reduces barrier function. In addition, xerosis increases transepidermal water loss in affected and clinically normal skin, and also exacerbates the symptoms of dryness, itching and burning.
Dermatitis is inflammation of the dermis exhibiting spongiosis or fluid between the cells, notes Dr. Dockery. He notes the acute form of dermatitis has blistering (vesicles), the subacute form features scaling and crusting, and the chronic form has lichenification. He notes that spongiotic dermatitis is not a precise clinical entity and that the term only describes the histopathologic presence of spongiosis.
Classic manifestations of spongiotic or eczematous dermatitis include atopic dermatitis, eczema, allergic contact dermatitis, nummular dermatitis and dyshidrotic dermatitis, notes Dr. Dockery. He cites additional conditions that may exhibit spongiosis, such as early-evolving psoriasis, stasis dermatitis, some drug reactions, arthropod assaults, parasite infestations, cellulitis/bacterial infections, trauma and tinea pedis.
When you see a rash, Dr. Dockery warns against assuming the condition is a fungus. He also points out that steroids can make fungal and yeast infections flare and slow the treatment when clinicians attempt to add steroids to antifungals.2–6 As Dr. Dockery says, the American Academy of Dermatology recommends against adding steroids to antifungals in the treatment of lower extremity dermatitis.7
A Closer Look At Corticosteroids For Dermatitis
After initially diagnosing the patient with spongiotic dermatitis or eczematous dermatitis, Dr. Dockery says the initial course should include steroid medication with topical steroids being the gold standard for treatment. He notes the type and quality of steroids depends on the patient’s Fitzpatrick skin type, whether the dermatitis is chronic or acute, and the location of involvement. Topical corticosteroids work because of their effects on vasoconstriction, immunosuppression and inflammation as they act to decrease redness, itching and swelling.
Dr. Dockery notes that current recommendations involve four classes of corticosteroids: super potent, potent, moderate, and low potency.8
Dr. Dockery says the delivery vehicle of topical corticosteroids can change the potency of the agent. As he points out, the occlusive effects of ointments are ideal for dry, thick or hyperkeratotic skin, but ointments are too greasy for hairy areas. He cautions that patients often dislike the feel of ointments and become non-adherent. The vanishing nature of creams increases their cosmetic appeal but decreases the steroid’s effectiveness, says Dr. Dockery. On acutely exudative or wet lesions, he notes creams can speed drying. Alcohol- or lubricant-based lotions feel better on hairy areas, and he adds that patients with acute exudative lesions prefer alcohol-based lotions whereas people with chronic dry lesions prefer lubricant-based lotions. Gels have drying effects due to their water and alcohol content. Dr. Dockery notes gels are good for wet, oozing rashes such as those caused by poison oak or ivy.
One may use topical steroids in combination with a urea-based keratolytic agent for patients with thickened or scaly skin, notes Dr. Dockery. He says one may also use topical steroids combined with moisturizers and/or topical immunomodulators for eczematous dermatitis.
Differentiating Common Lower Extremity Skin Lesions And Soft Tissue Masses
Dermatofibroma is the most common acquired benign skin tumor, notes Jeffrey D. Lehrman, DPM, FASPS. As he says, dermatofibroma, which often arises in multiple lesions, consists of a benign fibrous nodule on the skin surface and is mobile within subcutaneous tissue.
Folliculitis involves infection of hair follicles, which can be caused by shaving, tight clothes or rubbing, according to Dr. Lehrman. He says the affected skin can itch, burn or fill with fluid.
Psoriasis appears as plaques, spots or bumps that can be red, scaly or itchy, notes Dr. Lehrman. Psoriasis frequently occurs on knees, elbows and the scalp.
Dr. Lehrman explains that lichen planus is an autoimmune disease, which manifests as papules or plaques, and is mostly purple or violet in color.
Basal cell carcinoma, a locally invasive skin tumor, grows slowly and is subject to possible spontaneous bleeding or ulceration, notes Dr. Lehrman. He says basal cell carcinoma is pink or pigmented, and can vary in size.
Squamous cell carcinoma is a well-defined plaque and Dr. Lehrman notes its appearance can be crusty, ulcerated or scaly. He says the condition is an invasive disease that occurs when cancer cells have grown beyond the epidermis. Squamous cell carcinoma can metastasize and almost always requires surgical treatment, according to Dr. Lehrman. Bowen’s disease is a superficial form of squamous cell carcinoma. Dr. Lehrman notes this disease involves a solitary, well-defined red plaque with thick scaling.
In situ melanoma is confined to the epidermis, invasive melanoma has spread to the dermis and metastatic melanoma has spread to other tissues, notes Dr. Lehrman. He emphasizes using the ABCDEs of melanoma for diagnosis. These consist of Asymmetry, Border irregularity, Color variation, Diameter over 6 mm, and Evolving.
Expert Insights On Biopsy Techniques And Principles
When is a biopsy for a skin condition really necessary? Dr. Dockery cites several criteria: When the condition isn’t responding to therapy, when you don’t know what the condition is, when you want verification of the diagnosis and if malignancy is in the differential diagnosis. He also suggests biopsying any pigmented lesion larger than 6 mm in diameter and biopsying if the patient is concerned about the condition.9
When preparing the skin, Dr. Dockery suggests cleaning the skin of debris or soil, and prepping with 70% isopropyl alcohol, chlorhexidine or a Betadine solution.10,11
For injecting anesthesia, Dr. Dockery recommends using a 1 mL locking syringe and a 30 g needle. Hold the needle at a 30- to 45-degree angle to the skin, bevel the needle down and injecting at the dermis and subcutaneous junction.
As Dr. Dockery notes, the types of biopsy techniques include shave, saucerization, punch and excision.
Dr. Dockery says one would use a shave biopsy for elevated, pigmented or small-based benign lesions. He emphasizes that clinicians should always include the dermis when obtaining a shave biopsy specimen. Dr. Dockery also suggests the use of the Miltex Silicone Scalpel Blade (Integra LifeSciences).
Dr. Lehrman cites a range of CPT codes for a shave biopsy of the foot. CPT 11300 includes lesions 0.5 cm or less, CPT 11301 is for lesion diameter 0.6 to 1.0 cm, CPT 11302 is for lesion diameter 1.1 to 2.0 cm and CPT 11303 is for lesion diameter over 2.0 cm. As for shave biopsy of the feet, CPT 11305 is for lesion diameter 0.5 cm or less, CPT 11306 is for lesion diameter 0.6 to 1.0 cm, CPT 11307 is for lesion diameter 1.1 to 2.0 cm and CPT 11308 is for lesion diameter over 2.0 cm, notes Dr. Lehrman.
Dr. Dockery says the saucerization biopsy is usually deeper than a shave biopsy. A razor blade or BiopBlade (Integra LifeSciences) are preferable for this. As he notes, the sharpest blade is the double-edged razor blade (0.395 N) followed by the BiopBlade (0.46 N), plastic-handled #15 (0.541 N), the #10 blade (0.647 N), and the #15 blade (0.664 N).12
A punch biopsy is the most useful technique, notes Dr. Dockery. Sizes can vary with 2 to 4 mm the usual diameters. With a punch biopsy, he says one would spread the skin with the thumb and put the index finger against the relaxed skin tension lines. Place traction on either side of lesion, align with skin lines/creases and create an oval defect. He says one would take full skin thickness to the subcutaneous level while being careful of underlying tissues.
With a punch biopsy, Dr. Dockery cautions that one should remove the specimen carefully without using forceps and spear the specimen deeply with a needle or skin hook without damaging it. Ideally, he says one would obtain two 2 mm punches rather than one 4 mm punch. Dr. Dockery says this approach provides a more thorough sampling of the condition.13
The CPT code 11100 covers punch biopsy, according to Dr. Lehrman, for “Biopsy of skin, subcutaneous tissue and/or mucous membrane (including simple closure), unless otherwise listed; single lesion.” One would use CPT 11101 if he or she is obtaining multiple punch biopsies.
What is the best place to biopsy? Dr. Dockery suggests sampling the most representative site, the darkest area and the most elevated area. He advises biopsying any blister or vesicle, and any active edge or border. Clinicians should avoid obtaining biopsy specimens from the central area of the lesion (unless it matches the aforementioned criteria), normal skin and areas that look healed.
Finally, Dr. Dockery suggests sending all biopsy specimens to a dermatopathologist rather than a general pathologist.
References
1. Rawlings AV. Trends in stratum corneum research and the management of dry skin conditions. Int J Cosm Science. 2003; 25(1–2):63–95.
2. Smith EB, Breneman DL, Griffith RF, et al. Double-blind comparison of naftifine cream and clotrimazole/betamethasone dipropionate cream in the treatment of tinea pedis. J Am Acad Dermatol. 1992;26(1):125–7.
3. Wortzel MH. A double-blind study comparing the superiority of a combination antifungal (clotrimazole)/steroidal (betamethasone dipropionate) product. Cutis. 1982;30(2):258–61.
4. Katz HI, Bard J, Cole GW, et al. SCH 370 (clotrimazole-betamethasone dipropionate) cream in patients with tinea cruris or tinea corporis. Cutis. 1984;34(2):183–8.
5. Smith ES, Fleischer AB Jr., Feldman SR. Nondermatologists are more likely than dermatologists to prescribe antifungal/corticosteroid products: an analysis of office visits for cutaneous fungal infections. J Am Acad Dermatol. 1998;39(1):43–7.
6. Ference JD, Last AR. Choosing topical corticosteroids. Am Fam Phys. 2009;79(2):135-140.
7. Greenberg HL, Shwayder TA, Bieszk N, Fivenson DP. Clotrimazole/betamethasone diproprionate (Lotrisone): a review of costs and complications in the treatment of common cutaneous fungal infections. Pediatr Dermatol. 2002;19(1):78-81.
8. Jacob SE, Steele T. Corticosteroid classes: a quick reference guide. J Am Acad Dermatol. 2006 Apr;54(4):723-727.
9. Dockery G, Bakotic BW: Biopsy techniques. In: Lower Extremity Soft Tissue & Cutaneous Plastic Surgery, Ch. 13, Elsevier (Saunders), Philadelphia, 2012, pp. 127-141.
10. Dzubow LM, Halpern AC, Leyden JJ, et al. Comparison of preoperative skin preparations. J Am Acad Dermatol. 1988; 19(4):737-741.
11. Hemani ML, Lepor H. Skin preparation for prevention of surgical site infection. Rev Urol. 2009; 11(4):190-195.
12. Awadalla F, Hexsel C, Goldberg LH. The sharpness of blades used in dermatologic surgery. Dermatol Surg. 2016; 42(1):105-107.
13. Todd P. Evaluation of the 2-mm punch biopsy in dermatological diagnosis. Clin Exp Dermatol. 1996; 21(1):11-12.
