There are various acute dermatologic conditions that can present with symptoms of moderate to severe cutaneous pain. Examples of such painful dermatologic disorders include, but are not limited to, the continuum of Stevens-Johnson syndrome and toxic epidermal necrolysis, pyoderma gangrenosum (PG), hidradenitis suppurativa, and calciphylaxis. Involvement of dermatology consultants early on in presentation is recommended for diagnostic and therapeutic guidance for all acute dermatologic disorders. Pain management is an important aspect of therapeutic management in acute dermatologic disorders, and it is frequently guided by the World Health Organization’s proposed analgesic ladder for stepwise approach to pain management.¹

Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) make up a continuum of severe cutaneous adverse reactions that are characterized by fever, systemic disturbance, and significant epidermal sloughing that is associated with high morbidity and mortality. SJS/TEN are commonly triggered by various medications (eg, sulfa drugs, antiseizure drugs, and antibiotics), and as such, rapid recognition of SJS/TEN and withdrawal of culprit medications are critical for adequate control and reduction in mortality of this severe reaction. The mainstay of treatment for SJS/TEN is supportive care.

Stevens-Johnson syndrome and toxic epidermal necrolysis are characterized by painful mucocutaneous necrosis and epidermal detachment (Fig. 22.1) and, together, are part of a disease continuum classified based on pattern of lesions and on extent of epidermal detachment. SJS is classified by widespread erythematous macules with detachment of epidermis, affecting <10% of body surface area, whereas TEN involves detachment of epidermis above 30% of body surface area. SJS/TEN overlap is a third classification, which describes patients with epidermal detachment between 10% and 30% of body surface area² (Fig. 22.2). Differential diagnosis for presentation includes viral exanthems, other drug rashes, and erythema multiform; however, SJS/TEN may be differentiated by its characteristic severe cutaneous pain.

Cutaneous pain is a prominent feature in SJS/TEN, with skin pain often out of proportion to cutaneous findings. The presence of severe dermatologic pain should alert evaluating physicians to consider SJS/TEN on the differential, for early recognition is imperative for reduction in mortality. Dermatology consultation should be made as soon as possible to further guide diagnosis and management. Diagnostic workup may involve skin biopsy for histopathologic examination; however, histologic findings are neither specific nor diagnostic. Diagnosis relies heavily on the presence of clinical features, which include history of drug exposure, prodrome
of fever and malaise, painful progressive rash, severely painful mucosal erosions, and positive Nikolsky sign.³

Early recognition and withdrawal of suspected culprit medication is imperative for adequate control of the reaction and for reduction in mortality of SJS/TEN. Early withdrawal of the culprit medication may reduce risk of death by 30% for each day before development of blisters and erosions.⁴ Common culprit medications include antibiotics (eg, sulfamethoxazole, doxycycline), antiepileptic drugs (eg, lamotrigine, carbamazepine), allopurinol, and nonsteroidal anti-inflammatory drugs (eg, diclofenac).

Management of SJS/TEN consists of supportive care, including wound care, nutritional support, infection prevention, and pain control. Depending on severity of disease and percent of body surface area affected, patients may require transfer to a burn center or medical ICU experienced with managing patients with SJS/TEN for advanced supportive care. Pain management is a significant feature of SJS/TEN management as cutaneous pain is a prominent feature of the SJS/TEN reaction, with severe skin pain often out of proportion to cutaneous findings and most severe at sites of epidermal detachment. Cutaneous pain will also further be exacerbated by wound care procedures such as dressing changes. While there have been no studies comparing different analgesic regimens in patients with SJS/TEN, treatment is typically initiated based on the World Health Organization’s step-wise analgesic ladder.⁵ Therefore, treatment of SJS/TEN pain depends on intensity of pain, which can be described numerically on a scale of increasing severity from 0 to 10. For mild pain with intensity rating <4, patients may be treated with oral nonopioid analgesics (eg, aspirin, acetaminophen) that may be supplemented with mild oral opioids (eg, codeine) or synthetic opioids (eg, tramadol). For moderate to severe pain with intensity >4, patients should receive regularly scheduled opioids (eg, morphine, fentanyl) delivered enterally, by PCA, or by infusion, with regular around-the-clock re-evaluation of pain score (Fig. 22.3). For severe pain uncontrolled by standard adjuncts and parenteral opioids, patients may require ketamine-based sedation or general anesthesia.⁶

Pyoderma gangrenosum is a rare inflammatory and ulcerative neutrophilic dermatosis that ranks among the most painful of skin disorders.¹