Dermatology appeals: biologics and beyond

If you work in dermatology billing, you already know that biologics are where appeals get won or lost. The step therapy requirements, the biosimilar substitution debates, the constantly shifting payer criteria for psoriasis, atopic dermatitis, and hidradenitis suppurativa — all of it makes biologic authorization and appeals one of the most technically demanding areas in specialty billing. Heading into the back half of 2026, enough has changed that it's worth a hard look at where denials are coming from and how to fight them more effectively.

The biologic denial picture right now

Payers have gotten significantly more aggressive with step therapy enforcement, particularly for the IL-17 and IL-23 inhibitors that have become frontline treatments for moderate-to-severe plaque psoriasis. Denials citing "failure to try preferred agents first" are common even when your patient has already tried and failed those agents, just not in the order the payer's current formulary demands.

A few denial patterns worth watching:

• Biosimilar redirection denials: Your patient's dermatologist prescribes a specific biologic, the payer denies coverage because a biosimilar is now available. These are winnable if the prescriber can document clinical rationale, but the language matters.
• Step therapy "reset" denials: The payer changes its preferred agent list, and the patient's prior treatment history no longer satisfies the new pathway, even if it would have last year.
• Inadequate trial documentation: The denial says the patient hasn't adequately tried a preferred agent, but your records show they did. This is usually a documentation and submission problem, not a clinical one.
• Diagnosis specificity mismatches: Billing psoriasis without specificity (plaque vs. guttate vs. pustular) or failing to code severity (BSA, PASI scores) leaves gaps payers are quick to exploit.

Which pattern you're dealing with determines the entire appeal strategy.

Building a stronger foundation before you even appeal

The strongest appeals are built before the denial happens. That sounds obvious, but in practice there's usually a gap between what the clinical team documents and what the billing team actually receives to work with.

For biologics specifically, make sure your intake process captures:

• PASI or BSA scores at treatment initiation — payers want objective severity, not just "moderate-to-severe"
• Prior treatment dates and outcomes, including why each agent was discontinued (lack of efficacy vs. adverse event vs. patient preference, since these matter differently to different payers)
• Comorbidities that may influence treatment selection, such as psoriatic arthritis, IBD, or cardiovascular disease
• Prescriber rationale for choosing a specific agent over a biosimilar or preferred alternative

Appeals fail regularly because the documentation submitted is vague or incomplete, even when the clinical case is strong. "Patient failed methotrexate" doesn't hold up. "Patient completed a 16-week trial of methotrexate at 25mg/week with documented PASI scores of 14 at initiation and 12 at week 16, meeting criteria for inadequate response per the prescribing dermatologist's assessment" — that's what holds up.

Writing the appeal: what actually moves the needle

Structure matters once you're in appeal territory. Medical reviewers aren't reading your letter the way a colleague would; they're scanning for specific clinical checkboxes. Lead with what they're looking for.

Address the denial reason first, directly. Don't bury your strongest argument. If the denial is step therapy, the first paragraph should establish exactly how the patient has met the payer's step therapy criteria, citing specific policy language where you have it.

Use the payer's own policy language. Pull the actual coverage determination or clinical criteria document for that payer and that indication. Quote it. Show where your patient's case satisfies each criterion. That gives the reviewer something concrete to check, which a generic "the treatment is medically necessary" argument does not.

Anchor to specialty society guidelines. For dermatology biologics, the AAD clinical guidelines and published literature on treatment-resistant psoriasis are well-recognized. Citing them doesn't guarantee a win, but it signals that the appeal is clinically serious.

Ask for peer-to-peer review in the appeal letter itself. For high-dollar biologic denials, don't wait to be offered a P2P. Request it proactively. Dermatologists who are comfortable on peer-to-peer calls often turn around denials that written appeals alone can't.

One practical note: EZAppeal drafts appeal and prior-authorization letters in a few minutes, citing the payer's policy when one is on file, for your team to review and send. It does not replace clinical judgment, but it takes the first draft off the team's desk and keeps each criterion in view.

Hidradenitis suppurativa and atopic dermatitis: the often-overlooked problem areas

Psoriasis gets most of the attention in biologic discussions, but HS and atopic dermatitis appeals have their own quirks worth flagging.

For hidradenitis suppurativa, Hurley staging documentation is often missing or insufficiently detailed in the records submitted with an appeal. Payer coverage policies commonly ask for Hurley Stage II or III to justify biologic therapy, and if that staging isn't explicitly documented, the appeal starts at a disadvantage.

For atopic dermatitis, the documentation bar depends on the drug. Policies for dupilumab and the oral JAK inhibitors commonly ask for documented trials of topical therapy, and some, particularly for the JAK inhibitors, also ask for a prior systemic therapy. Exact criteria vary by payer, so pull the policy for the specific drug before you appeal.

DLQI (Dermatology Life Quality Index) documentation helps in both areas. Some payers don't require it explicitly, but including it paints a fuller picture of disease burden and strengthens the clinical narrative in ways that purely objective metrics often don't.

Practical next steps for your team

If biologic appeals are a recurring problem in your practice or RCM workflow, here's where to focus:

1. Audit your denial patterns from the past 90 days. Categorize them: step therapy, biosimilar, documentation gaps, coding issues. The pattern tells you where to fix the process.
2. Build a biologic appeal template library organized by condition and denial type. Drafting from scratch every time is inefficient and inconsistent.
3. Get the clinical team aligned on documentation standards. A short conversation with your dermatology providers about what payers actually need to see is worth more than any single well-written appeal letter.
4. Track appeal win rates by payer and denial reason. If most of your IL-23 inhibitor appeals to one payer come back denied again, that's a pattern worth escalating or researching specifically.

Many biologic denials in dermatology turn on documentation and submission details rather than the clinical case, which means the right documentation and structure can turn them around. A repeatable appeals process serves the team better than treating each denial as a one-off event.