Recurrent Painful Patches

A 20-year-old Caucasian male presents to the clinic with a 1 year history of recurrent pruritic irritable patches. The rash presented in the axillae and progressed to include other areas of friction, such as the waistline and popliteal fossa. The patches responded to topical corticosteroids but would recur when therapy was discontinued. The patches are worsened by exercise and heat. The most symptomatic lesions are over his buttocks, anterior thighs, waistline, and axillae. The patient denies fever, fatigue, and night sweats. Past medical history is unremarkable. 

Physical exam revealed erythematous patches and plaques with thin confluent scale and thin fissures on the right medial biceps, right abdomen, waistline, and bilateral buttocks. There is minimal petichae scattered throughout the patches (Figure). 

Figure. Right waistline, an erythematous patch with minimal petechiae scattered throughout. Note the similarity to allergic contact dermatitis.

The patient was diagnosed with mycosis fungoides, the most common cutaneous T cell lymphoma (CTCL) which is a malignancy of CD4-positive T cells of unknown etiology.¹ It may manifest as erythematous pruritic patches, plaques, and or large necrotic tumors.^2,3 The lesions may be ill or well defined. Typically the lesions first appear in non-sun exposed areas and evolve from patches to plaques and then tumors. Alopecia and generalized erythroderma may also be present. 

Progression of the disease is marked by atypical lymphocytes which have lost their affinity for the epidermis and infiltrate the dermis, blood, and lymph nodes.³ The incidence of MF which has been increasing is 6.4 per million, is higher in blacks than whites, more common in men, with the average age of onset between 55 and 65.⁴ 

Initial presentation may resemble contact dermatitis, eczema, or psoriasis. As the disease progresses the T lymphocyte population is destroyed and the patient becomes immunocompromised. Mortality is often due to infections from necrosis and ulceration of lesions.⁵ A skin biopsy of the lesion will reveal atypical lymphocytes infiltrating the epidermis or dermis if advanced. While not common, the pathognomonic finding for mycosis fungoides is Pautrier’s microabscesses.⁶ The indolent and misleading nature of this disease presents a diagnostic challenge which can often lead to a delay in treatment. 

In this case, biopsy confirmed the diagnosis of mycosis fungoides. Biopsy revealed infiltration of monoclonal lymphocytes within the papillary dermis characteristic of MF. ■

References:

1.Agar NS, Wedgeworth E, Crichton S, et al. Survival outcomes and prognostic factors in mycosis fungoides/Sézary syndrome: validation of the revised International Society for Cutaneous Lymphomas/European Organisation for Research and Treatment of Cancer staging proposal. J Clin Oncol. 2010;28(31):4730-4739. 

2.Burg G, Kempf W. Etiology and pathogenesis of cutaneous lymphomas. In: Burg G, Kempf W. Cutaneous Lymphomas. London: Taylor & Francis; 2005. 

3.Habif TP. Clinical dermatology: A color guide to diagnosis and therapy. 5th ed. Elsevier Inc;2010.   

4.Criscione VD, Weinstock MA. Incidence of cutaneous T-cell lymphoma in the United States, 1973-2002. Arch Dermatol. 2007;143(7):854-859. 

5.Tsambiras PE, Patel S, Greene JN, Sandin RL, Vincent AL. Infectious Complications Of Cutaneous T-Cell Lymphoma. Cancer Control. 2001;8(2).  

6.Wolff K, Johnson R. Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology. 5th ed. McGraw-Hill; 2005.